By Huzaifa Alam, EasyYTDown · Updated September 27, 2026
When downloading from YouTube, the first decision you make is format: MP4 or MP3. It seems simple — video or audio — but the right choice depends on what you plan to do with the file, which devices you will use, and how much storage you have.
The One-Line Answer
Download MP4 if you want to watch the video. Download MP3 if you only need the audio. The rest of this guide covers the trade-offs: file size, compatibility and audio quality.
What Is MP4?
MP4 (MPEG-4 Part 14, standardised as ISO/IEC 14496-14) is a digital multimedia container format. It stores video, audio, subtitles, and metadata together in one file. When you download a YouTube video as MP4, you get the complete visual and audio experience — exactly what you would see on YouTube, saved to your device.
MP4 is one of the most widely supported video formats. It plays natively on:
- Windows (the built-in Media Player or Films & TV app)
- Mac (QuickTime)
- iPhone and iPad (Files app, Photos)
- Android (any default video player)
- Smart TVs, PlayStation, Xbox
- VLC and every major media player
You will rarely find a device that can't play an MP4 file.
What Is MP3?
MP3 (MPEG-1 Audio Layer III, defined in ISO/IEC 11172-3) is an audio-only format. When EasyYTDown creates an MP3 from a YouTube video, it extracts just the audio track and discards the video. The result is a smaller file that contains only sound — no picture, no video stream.
MP3 plays on:
- Practically every phone, tablet and computer
- Car stereos (via USB, Bluetooth, or CD-R)
- iPods and other MP3 players
- Smart speakers (Amazon Echo, Google Home via Bluetooth)
- Most podcast and music apps that support local files
If a device can play audio, it almost certainly supports MP3.
MP4 vs MP3 — Head-to-Head Comparison
File Size Difference — Why It Matters
The most practical difference between MP4 and MP3 is file size. A 10-minute YouTube video:
- As MP4 at 720p: approximately 150–300 MB
- As MP4 at 1080p: approximately 300–600 MB
- As MP3 at 128kbps: approximately 9–12 MB
MP3 is roughly 10–30x smaller than a 720p–1080p MP4. This matters when you have limited storage on your phone or want to download many items. If you are saving a 2-hour lecture for the train, as MP4 it might be 2–4 GB. As MP3 at 128 kbps, it is about 115 MB.
When to Download as MP4
- You need to see what is happening: Tutorials, demonstrations, documentaries, vlogs, sports — anything where the visuals matter
- You are watching on a TV or large screen: MP4 at 1080p looks great; there is no video version of MP3
- The visual information is essential: Cooking videos, how-to guides, nature documentaries
- You might want the picture later: you can always extract audio from an MP4, but you can't get the video back from an MP3
When to Download as MP3
- Music and songs: You only need to hear the music, not watch the music video
- Podcasts: Many podcasters post to YouTube — MP3 lets you add them to your podcast app
- Lectures and educational talks: If you can follow along without watching the screen (most lectures), MP3 saves huge amounts of storage
- Motivational speeches and TED Talks: Pure audio is usually enough for spoken content
- Language learning audio: Repeat playback of pronunciation examples, dialogues, and exercises
- Background listening: Content you play while cooking, exercising, or commuting
- Storage-limited devices: If your phone has 2 GB free and you want 10 hours of content, MP3 is the only practical choice
Audio Quality in MP4 vs MP3
The audio inside an MP4 and an MP3 made from the same video can sound the same. YouTube streams compressed audio (AAC or Opus), so neither download can sound better than YouTube itself. When EasyYTDown creates an MP3, it uses the MP3 encoder's highest variable-bitrate setting, and any loss from that conversion is very hard for most listeners to hear.
Neither option is lossless. The audio inside EasyYTDown's MP4 files is also converted (to AAC), so neither format is a bit-for-bit copy of YouTube's audio. For everyday listening the difference isn't noticeable.
Can You Extract Audio from an MP4 File Later?
Yes. If you downloaded MP4 and later want just the audio, you can extract it using free tools:
- VLC Media Player: File → Convert / Stream → select audio-only MP3 output
- FFmpeg (command line):
ffmpeg -i video.mp4 -q:a 0 -map a audio.mp3 - Audacity: Open the MP4 file and export as MP3
- Online converters: Various browser-based tools convert MP4 to MP3 without software
The reverse — adding video to an MP3 — is not practically useful, so if you think you might want the video later, download MP4 to begin with.
What About Other Formats — WebM, MKV, AVI?
YouTube offers each video in several formats, including WebM (VP9 or AV1 video with Opus audio) and MP4 (H.264 video). EasyYTDown picks the H.264 MP4 stream because it has the broadest compatibility. You will occasionally see other formats mentioned:
- WebM: good quality and often smaller than MP4, but less widely supported, especially on older players and some Apple devices
- MKV: flexible and popular for high-quality video, but less widely supported than MP4 on phones
- AVI: Old format, large files, not recommended for modern use
- AAC: Better audio quality than MP3 at the same bitrate — but MP3 is more universally compatible
For most users, MP4 for video and MP3 for audio avoids compatibility problems.
Frequently Asked Questions
Can I play MP3 files downloaded from YouTube in Spotify or Apple Music?
Spotify can play local MP3 files: you enable local files in its settings on desktop, and they can then be synced to your phone. Apple Music also lets you add MP3 files to your library and sync them to your iPhone. VLC and similar apps play MP3s on any platform without restrictions.
I downloaded MP4 but I only hear audio — is it broken?
No. An MP4 file plays both video and audio. If you only hear audio, your media player may not support the video codec. Install VLC Media Player (free) and try again — it plays all MP4 variants.
Which format downloads faster — MP4 or MP3?
MP3 downloads are generally faster because the file is much smaller. An MP3 from a 10-minute video is roughly 10–20 MB; the MP4 version at 720p is typically 150–300 MB.
Which is better for WhatsApp sharing — MP4 or MP3?
WhatsApp supports both MP4 video files and MP3 audio files. For video sharing, use MP4. For audio messages or music sharing, MP3 is smaller and faster to send. WhatsApp limits the size of files you can send, so long videos may need to be sent as a document or at a lower quality.
Is MP3 free to use on EasyYTDown?
MP3 extraction is a Pro feature on EasyYTDown ($4.99/month). MP4 video downloads in 360p, 480p, and 720p are available free (5 downloads/day, no sign-up).
Summary — Choose Based on Your Use Case
The format decision is straightforward once you know what you need:
- Need to see it → MP4
- Only need to hear it → MP3
- Watching on a big screen → MP4 at 1080p
- Limited storage → MP3
- Adding to a podcast app → MP3
- Sharing a funny clip → MP4
Ready to download? Use the MP4 downloader (free up to 720p) or the MP3 converter (Pro). Not sure which video quality to pick? See the YouTube quality guide.
Sources
- ISO/IEC 14496-14:2020: MP4 file format
- ISO/IEC 11172-3:1993: MPEG-1 audio (includes Layer III, i.e. MP3)